But a dozen is the number of so-called "enduring bases" located by John Pike, director of GlobalSecurities.org. His military affairs website gives their names. They include, for example, Camp Victory at the Baghdad airfield and Camp Renegade in Kirkuk. The Chicago Tribune last March said US engineers are constructing 14 "enduring bases," but Mr. Pike hasn't located two of them.

Note the terminology "enduring" bases. That's Pentagon-speak for long-term encampments - not necessarily permanent, but not just a tent on a wood platform either. It all suggests a planned indefinite stay on Iraqi soil that will cost US taxpayers for years to come.

The actual amount depends on how many troops are stationed there for the long term. If the US decides to reduce its forces there from the 138,000 now to, say, 50,000, and station them in bases, the costs would run between $5 billion to $7 billion a year, estimates Gordon Adams, director of Security Policy Studies at George Washington University in Washington, D.C. That's two to three times as much as the annual American subsidy to Israel. Providing protection for Israel is one of several reasons some analysts cite for the US invasion of Iraq.

If more troops are based in Iraq for the long haul, the cost would be higher. US Army planners are preparing to maintain the current level of forces in Iraq at least through 2007, The New York Times reported this week. But no decision has been made at the political level.

So far, the Bush administration has not publicly indicated that it will seek permanent bases in Iraq to replace those recently given up in Saudi Arabia, a possibility mentioned by Deputy Defense Secretary Paul Wolfowitz before US forces moved into Iraq. The US already has bases in Kuwait and Qatar.

At an April 2003 press conference, Defense Secretary Donald Rumsfeld said any suggestion that the US is planning a permanent military presence in Iraq is "inaccurate and unfortunate." With the presidential election weeks away, he is unlikely to alter that pronouncement on such a politically touchy matter. Such a move would almost certainly attract fire from Democratic candidate John Kerry.

Nonetheless, several military experts in Washington assume Iraq's new government will need the support of American troops - and thus "permanent" bases - for years, perhaps decades, to come.

The US already has 890 military installations in foreign countries, ranging from major Air Force bases to smaller installations, say a radar facility. Perhaps bases in Iraq would enable the Pentagon to close a few of those facilities. As part of a post-cold-war shift in its global posture, the Defense Department has been cutting the number of its installations in Germany, which total more than 100. Last week Mr. Rumsfeld testified about a global "rearrangement" of US forces to the Senate Armed Forces Committee.

"Who needs Germany when we have Iraq?" asks Mr. Pike of GlobalSecurities.org.

Building bases in Iraq has risks. Two Americans beheaded last week were working as civil engineers constructing the Taji military base north of Baghdad, one of the bases Pike lists as "enduring."

The bigger risk: Polls find that at least 80 percent of Iraqis - whatever their views on the insurgency, democracy, the removal of Saddam Hussein, and other issues - want US armed forces to leave their nation. Making the bases permanent could stir up more opposition to the US occupation.

Another fear, however, is that without US bases, the various Iraqi factions - the Shiites, Sunnis, and Kurds - would fall into civil war. In turn, this conflict could drag in Iran, Syria, and Turkey, leading to a widespread conflict in the Middle East. Hope of establishing a democracy in an Arab nation would fade.

To avoid these risks, an Iraq government will accept a US military presence despite popular disapproval, Pike says. "An indefinite American presence in Iraq is the ultimate guarantor of some quasi-pluralistic government."

Also, withdrawal of US forces would be seen by Iraqi insurgents as a victory, prompting them to redouble their efforts to kill Americans, says Thomas Donnelly, a military expert at the American Enterprise Institute in Washington.

The US can afford maintaining bases in Iraq, he argues. US defense spending now amounts to a bit more than 4 percent of gross domestic product, the nation's output of goods and services. It might rise as a result of Iraq bases to 5 percent of GDP, still less than the 6.5 percent of GDP in the cold war or the 10 percent during the Vietnam War.

Not everyone agrees. Permanent bases in Iraq are a "disastrously bad idea," says Jessica Mathews, president of the Carnegie Endowment for International Peace in Washington. It reinforces Iraqi suspicions that the US launched the war to get a hand on Iraqi oil, control the region, and wants to maintain a puppet government in Baghdad.

The total cost of the Iraq war has reached $125 billion to $140 billion, estimates Mr. Adams. Reconstruction boosts the total to as high as $175 billion. Permanent bases would keep the tab running for years to come.